Climate Change

Executive Summary

There are important links between sustainable sanitation, climate change and renewable energy production. For example, sanitation systems can be designed in a way to produce renewable energy sources which in turn may mitigate climate change by reducing greenhouse gas emissions. Sanitation systems may also serve to help people adapt to climate change by reusing energy, nutrients and treated wastewater and thus substituting the use of primary resources.

Greenhouse Effect and Responsible Gases

The greenhouse effect is the phenomenon where the presence of so-called greenhouse gases leads to a warming of the earth's surface: Greenhouse gases allow solar radiation to enter the earth's atmosphere but prevent heat from escaping back to space. They absorb infrared radiation and reflect it to the earth's surface leading to a warming there. Many human activities cause greenhouse gas emissions which drive the anthropogenic greenhouse effect. According to the Intergovernmental Panel on Climate Change the atmospheric greenhouse effect will cause a rise in the mean global temperature of between 1.1 and 6.4°C by the end of the 21st century (IPCC 2007a), a change in rainfall patterns, a rising sea level and a weakening of sea currents which will have an additional impact on the global temperature distribution. In order to limit climate change to tolerable levels, global temperature rise has to be limited to 2°C (IPCC 2007b). To achieve this, greenhouse gas emissions would have to be reduced by 50% by 2050 compared to the level in 1990 (IPCC 2007c).

Relevant Greenhouse Gases

In the field of sanitation, the following greenhouse gases are climate relevant:

Carbon dioxide (CO2)is produced as a result of any fossil or non-renewable wooden biomass combustion. Similarly, the removal of organics and nutrients in wastewater treatment plants requires energy. The same holds true for the production of mineral fertilisers which is a very energy intensive process. Both the removal and the new production of nutrients for fertilisers require the consumption of fossil fuels leading directly to climate relevant CO2 emissions. For climate protection, it is important to reduce fossil or non-renewable wooden biomass consumption.

Mitigation and Adaptation in Sanitation

By using appropriate reuse-oriented sanitation systems with energy, nutrient or wastewater recovery and reuse, anthropogenic greenhouse gas emissions can be reduced (mitigation) as well as people's capacity to cope with climate change impacts can be increased (adaptation). In the field of sanitation, possible measures to mitigate or adapt to climate change impacts are described in the following sections about mitigation measures and adaptation measures.

Wherever biogas is produced, it must be captured and preferably used either for simple heat generation or for a combined heat and electricity generation, e.g. by means of a combined heat and power plant (see pictures below) or by a fuel cell. This can substitute the use of fossil or non-renewable energy sources. If the biogas cannot be used, then it has to be flared (this converts methane to carbon dioxide which has a 21 times lower greenhouse gas potential than methane, see section about relevant greenhouse gases). This results in the following recommendations:

In order to adapt to flooding, one effective measure consists of building sanitation system components in a way that they are either not affected by flooding (UDDTs built high enough above ground) or that water can evacuate quickly (elevated sludge drying beds, constructed wetland).

Emission Trading as an Additional Financial Benefit

The Kyoto Protocol – the internationally binding contract on climate protection measures valid until the end of 2012 – assigns each participant country which has emission reduction commitments an allowed amount of greenhouse gas emissions. In order to reach this emission target at the least macro economic costs, the Kyoto Protocol offers three market-based flexible mechanisms. One of them, the Clean Development Mechanism (CDM), is designed for trading emission reductions which have been achieved in developing countries.

The CDM can be used for emission reductions achieved through sustainable sanitation systems. It can contribute to an additional financial benefit but also generates CDM-related costs which are mostly fixed and which compensate achieved credits to some extent.

Hence, for sustainable sanitation systems, a minimum project scale is required to make CDM economically attractive. This is very much dependent on both the baseline and the project scenario, the energy demand of the fertiliser production plants, the energy mix of the country considered, the transaction costs and the price of the carbon credits.

Assuming average transaction costs and a long-term price of 20 €/CER, the minimum project scale was found in (OLT 2008) to be around 25 000 PE1 (for energy recovery) and 37 000 PE (for nutrient recovery). The minimum project scale for an economic use of CDM for energy recovery (biogas use) and nutrient recovery (urine use) was analysed for a case study in India (OLT 2008). From an emission reduction point of view, this project faced favourable conditions in view of energy recovery and unfavourable conditions in view of nutrient recovery. Therefore the above indicated project scale for energy recovery represents an absolute minimum value, while the value for nutrient recovery can also be lower.

In order to reach this number, similar CDM projects may be bundled to a "Programme of Activities" (PoA). A manual for biogas plants at household level is given in (GFA 2009). Further information on PoA is available at (UNFCCC 2009).

In many Asian countries, e.g. China, human excreta or so called "night soil" is being treated in this way together with animal manure and other organic waste. As a result of a Chinese national programme in the 1970s ("Biogas for every household"), the increasing energy demand and continuing efforts to combat wood cutting, there is an on-going interest in biogas which is supported by the Ministry of Agriculture. Today, there are five million family-sized plants in operation (BALASUBRAMANIYAM et al. 2008).

Biomass Production: Biomass is a non-fossil energy source which is neither always harmful nor always neutral to the climate. According to the UNFCCC definition (UNFCCC 2006), renewable biomass is understood as:

wood (provided that wood harvest does not exceed its growth)

other wooden biomass (provided that the cultivated area remains constant)

Both food and biomass production are essential for people's livelihoods, and often compete with each other for available land, water and nutrient resources. Food and biomass production might be seen as equally important in economically rich countries with a safe food supply. But in many developing countries food production takes priority, whilst at the same time most people are dependent on biomass (particularly wood) for their energy supply, primarily to cook their food. One way to establish whether priorities should tend towards either food or biomass production is to carry out a national food balance taking into account food production and food consumption (OECD-FAO 2008). This can then be used as a basis for making decisions regarding the cultivation of more food or more energy crops. The use of sanitation-derived fertilisers in agriculture may increase the productivity of the land and thus decrease the conflict between food and biomass production at the local level (see also short rotation plantations).

Conclusion

It has been shown that sustainable sanitation projects can contribute to both mitigate climate change (through energy or nutrient recovery) and to adapt to climate change (through an intelligent water and wastewater management). Measures of energy recovery (or: renewable energy production) consist basically of either biogas or biomass production while measures of nutrient recovery are primarily based on nitrogenreuse. Water and wastewater management measures aim at coping with either water scarcity or flooding.

Most of these measures lead to greenhouse gas emission reductions. In case they were achieved in developing countries, they can be sold on international emission allowances markets and thus contribute to an additional financial benefit. In order to be financially viable, a certain minimal project size must be realise.

A paper about how and why fertilisers are used. This includes also the energy lifecycle of fertilisers and, today even more important, measures which can improve the energy efficiency of fertiliser production and use.

A report by the World Health Organisation which reveals the impact of the climate change on human health worldwide. This includes several topics like climate extremes and infectious diseases which are linked with climate. It offers also an outlook into future and possibilities to response the threat.

Climate change has significant implications for freshwater infrastructure. Impacts such as increases in droughts and floods as well as changing precipitation patterns in countries across the world imply that development and conservation programs could fail to realize intended benefits or, worse still, contribute to increased exposure of populations to the hazards of climate change. However, freshwater infrastructure which is developed and operated in a sustainable and climate informed manor, can play a significant role in helping communities adapt while placing as little additional pressure on ecosystems as possible.

This publication first summarises the challenges facing agriculture and water without climate change. It then considers the broad and more specific impacts of climate change in different regions of the world, and looks at the options for adaptation and mitigation in some detail. It attempts to reach a practical focus without excessive generalisation.

This study aims to analyse climate related disasters risk reduction governance in the European context. There is a particular focus on the flow of information from researchers to policy makers and the way in which the decision-making process in climate adaptation and risk reduction is commonly managed. The study confines itself to Europe and looks into practical cases of European regional and national adaptation strategies.

This report is intended as a further step in a global dialogue to engage the international waste community, identify the key issues, and create a strategy that will deliver significant climate benefit in the waste sector.

This factsheet book is a compilation of 13 thematic factsheets which were produced by the eleven SuSanA working groups (WGs): WG1 - Capacity development; WG 2 - Finance and economics; WG 3 - Renewable energies and climate change; WG 4 - Sanitation systems, technology options, hygiene and health; WG 5 - Food security and productive sanitation systems; WG 6 - Cities and planning; WG 7 - Community, rural and schools (with gender and social aspects); WG 8 - Emergency and reconstruction situations; WG 9 - Sanitation as a business and public awareness; WG 10 - Operation and maintenance; WG 11 - Groundwater Protection. What makes these factsheets special is that they are multi-authored by people from different organisations and by free-lance consultants. The factsheets were developed in a long process involving many discussions and review loops which were mostly carried out in public, e.g. at working group meetings, with the working group mailing lists or, since July 2011, also in the open SuSanA discussion forum.

UN Water; UN Water (Editor) (2013): Water Security and the Global Water Agenda. Ontario: United Nations University, Institute for Water, Environment and Health (UNU-INWEH) and United Nations Water Programme (UN Water). URL [Accessed: 09.04.2013].

This analytical brief aims to define “water security” and urges to include water security on the agenda of the UN Security Council. It discusses the key aspects of water security (such as climate change, human rights, water food-energy-nexus among others) as well as its policy relevance and policy response options.

This paper addresses two knowledge gaps in the quantification of direct emissions of methane and nitrous oxide from wastewater treatment systems: the influencing factors of the magnitude of dissolved methane generation and subsequent unaccounted loss in low-strength anaerobic systems and the magnitude and variability of nitrous emissions from biological nutrient removal processes.

This book published by Eawag/Sandec compiles existing and recently generated knowledge on anaerobic digestion of urban biowaste at small and medium scale with special consideration given to the conditions prevailing in developing countries. Written for actors working in the waste and renewable energy sector, the book is divided into two parts: Part 1 focuses on practical information related to the anaerobic digestion supply chain (substrate-, process-, and product chain), and Part 2 presents selected case studies from around the world.

The Vision 2030 study aims to increase our understanding of how anticipated climate change may affect drinking water and sanitation systems and what can be done to optimize resilience of infrastructure and services.

The report investigates access to and use of drinking water in greater detail than is possible in the regular JMP progress reports, and includes increased disaggregation of water service levels and analyses of trends across countries and regions. It focuses on the three key challenges of equity, safety and sustainability.

Important Weblinks

This link gives an abstract about the United Nations Framework Convention on Climate Change (UNFCC), which was founded to cope with increasing temperature. The abstract includes registered programmes, which are ongoing.

Environmental Issues

Wastewater Treatment

There are hundreds of ways how wastewater can be treated in a sustainable manner that does not produce greenhouse gases. Particularly, anaerobic treatment methods with biogas collection and use are suitable. Learn more on them: